Safety device for elevator-cages



J. 'HOFFER.

V SAFETY DEVICE FOR ELEVATOR GAGES.

APPLICATION FILED FEB. 11. 1920.

WITNESS IS Patented Nov. 15, 1921.

UNITED STAES PATENT OFFICE.

e ew; ewe NSYL I sum? nnvrcr. roa ELEVATOR-GAGES.

To all whom it may concern:

Be it known that; I, J 01m HOFFER, residing at'Marianna, in "the county of .Washington and State of Pennsylvania, a sub ect of the former Kingdom of Hungary, in the former Austro-Hungarian Empire, have in- .ventedor discovered certain new and useful Improvements in Safety Devices for Elevator-Gages, of which improvements the following is a specification. I i

My invention relates to safety devices for elevator cages; and by the term elevator 1 cagessl meantoinclude in the field of in,- vention elevator structures,"whetheroperats ing in vertical shafts or runway: or on 'inclines, whether large. or small, and in whatever situationin buildings, in mines, on hillsides connecting :public highways, etc. I

The safety device upon which my present improvement is made includes, in combination with the car, traveling in its run- ;way,'and a :post extending longitudinally of the runway and adjacent thespath of car travel, a post-engaging member borne by the car,normally inactive, but cominginto postengaging position. automatically cwhen the car-sustaining "cable breaks, or when the speed of car travel exceeds" axpredetermined maximum, and by so coming to post-engaging position, arresting the car and, in case of a broken cable, sustainingit and preventing :its falling; I i 1 i i i i In the accompanying drawings, Figure I shows in side elevation an elevator .cariin position ina mine shaft and havingapphed to it the safety device of my: present. invention; II (is: a i view in, crosswsection through the mine shaft, showing the postssin section and the car in plan view from above. Fig. III is a view tolarger scale in cross section through the machine shaft by which the post-engagingmember (in this-case a cam) is moved and showing the cam itself in elevation. if

The elevator car is indicated by 1, and it is sustained and married by a cable 2. It travels in its shafttorrunway,itspath being ordinarily defined by guides such as 3. Two such guides are here shown, defining a vertical runway for the car 1. Such guideways convenientl become the posts upon which the safety evice acts, and such is the arrangement shown. All that is requisite of the posts is that they extend longitudinally of and. adjacent to thecar runway.

Specification of Letters Patent. Patented NO 15 i Application filed February 11, 1920; Serial No. 357,798.

Special posts may and in some cases must be provided for the proper functioning of the safety device, but in many cases it is convenient, as here shown, to employ the car guides 3 the postsnpon which the safety device acts. I

The safety device includes members which, normally inactive, move to post-engaging position on the transpiring of the emergency for which the safety: device, is in.- tended; In this case pairs of cams i, mounted on rotary shafts 5, are arranged on either side of each post3. Means are provided for turning these shafts and bringing the cams to post-enaging position. Such means are herefound in springs 65. Under all normal conditions of operation the cams are held re.- tracted and the springs under restraint, but, upon the transpiring of the emergency for which the safety device is intended, the

springs come into playand the cams cometo post engagement. The emergency here con templated is the parting of the car-sustaining cable 2. Shafts 5 are connected,,through arms 7 and chains8 tocableQ. This connection, so long asthe rope is taut and the weight of the car is. exerted on it,holds the hsafetyjdevice inactive; but, immediately this tension is by the partingof cable2 relieved, springs 6 acting through arms, 9 turncam and shaft] together and bring the cams to post-engagement. Thelarrangement is as shown preferably such that the weight. of the car tightens the bite of the cams upon the posts the double arrangement of: cams with the member of each pair coiiperating upon one and the same post, from opposite sides affords the clamping eflect desired.

There are three-features ofthe structure to which I here call attention, in which separately or collectively my present invention resides, Inthe first place, it is to be, ob-

served that the camsare mounted on separate; shafts, particularly that the opposite and axially alined cams aremounted on separate, 1 shafts. Ordinarily, simplicity of structure has dictated, that these Iopposite cams be carried by twos on single shafts; and this would be well enough, if the installation were alwa s" perfectly proportioned in all its parts. ut in-practice, particularly in coal mines, the posts 3 are formed of timbers which are prone to vary in minute dimension, are liable in the common run of such material to present irregularities, they By mounting each cam on its own separate and separately impelled shaft, faults in operation of this sort are prevented.

. In the second place, it will be observed of the springs 6, as'they are particularly shown in Fig. I, that by the turning of the nuts on bolts to which the springs are an chored, and so moving'the bolts longitudinally, the intensity of spring tension may be varied. This adjustability is advantageous in such apparatus, where long-coir tinned use may effect changes in the efficacy of parts.

In the third place, the individual cam is provided with two areas of post engaging surface. These areas come successively into engagement; one (the area 11) projects farther from the center of turning, is built on a longer'radius; is narrow, and is provided with relatively long sharp tines. It is indeed a. spur. The other and lowersurface 12 will ordinarily be faced with the usual irregularity, roughness or corrugation, effective to make ear-sustaining engagement with the surfaces of posts 10.

The difiiculty to the overcoming of which this last item of structure is directed is this: It sometimes happens, in consequence of misshaping, wear and distortion of parts, the

spreading of'water over wooden surfaces,

to render them slippery, and the like, that theordinary cams fail: to hold. They siip ofi the posts bulge and there is danger that the falling car will still escape from the proper action of the safety device. By providing the narrow sharp-tined'spur portion of the post-engaging cam surface insurance is had, against escape of the post and cam from engagement one with the other; and then, since the spur has been made relatively narrow to effect its end, the adjacent cam surface is provided, to come into play as the spur sinks into the wood of the post, to afford the normal and usual engagement over surfaces so extended as to insure security.

Variation in detail is of course permissible; the essential features of invention are defined in the ensuing claims.

. I claim as my invention:

1. In a safety device for elevator cages, the combination, with a car mounted in a runway and a post arranged adjacent the runway, of a post-engaging member borne by the car and movable to and from post-engaging position, the said member including two post-engaging cams turning in unison upon a common axis,the said cams being of unequal radii and the cam of larger radius being tined substantially as described.

2. In a safety device for elevator cages, the combination, with a car mounted in a runway and a post arranged adjacent the runway, of apost-engaging cam mounted on a center of turning in said car and including two post-engaging parts; a spur of relatively large radius, and a weight-sustaining part of less radius, substantially as described.

3. In a safety device for elevator cages the combination, with a car mounted in a runway, a car-sustaining cable, and a post arranged adjacent the runway, of a post-engaging member borne by the car, means for swinging said post-engaging member from inactive to active position, means for varying the intensity of such member-swinging means, and means rendered ineffective on the parting of the car-sustaining cable normally holding the member-swinging means inactive, substantially as described.

4. In a safety device for elevator cages the combination, with a car mounted in a runway and a plurality of posts arranged adjacent the runway and oneither side the car, of a cmresponding plurality of post-engaging members borne by the car and movable to and from post-engaging position, each of said members provided with two post-engaging parts coming successively into engagement with a post as the member moves, separate means for moving each of said members, and means for varying separately the effectiveness of each of the member-moving means last mentioned, substantially as described.

In testimony whereof I have hereunto set my hand.

JOHN HOFFER. Witnesses:

BAYARD H. CHRIs'rY, FRANCIS J. TOMASSON. 

